Answer: Hostas, especially the "blue" hostas would be a good choice for deep shade. The variegated hostas will bring some foliage contrast to help lighten the look of the area. Liriope will grow there, as will mondo grass (Ophiopogon). Also consider ferns. Some additional perennials to consider would include Aruncus (Goatsbeard), Epimedium, Dicentra, Cimicifuga (Bugbane), Tiarella, Tricyrtis, and Polygonatum (Solomon's Seal). Heuchera or coral bells would prefer some direct sun or at least bright dappled light all day, in my experience it does not grow well in deep shade. If you like their look, you might try Heucherella which is a bit more shade tolerant (it is a cross between Tiarella and Heuchera.) I hope this gives you some ideas.
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